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Question
A body weighing 0.5 kg tied to a string is projected with a velocity of 10 m/s. The body starts whirling in a vertical circle. If the radius of the circle is 0.8 m, find the tension in the string when the body is at the top of the circle.
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Solution
Given:
m = 0.5 kg, u = 10 m/s, r = 0.8 m
To find: Tension at highest point (TH)
Formula: TH = `"m"/"r"("u"^2 - 5"rg")`
Calculation:
From formula,
TH = `0.5/0.8(10^2 - 5 xx 0.8 xx 9.8)`
= `0.5/0.8(100 - 39.2)`
= 38 N
The tension in the string when the body is at the top of the circle is 38 N.
Notes
Note - The given question is solved in accordance with the textbook method.
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